Abstract

We are examining diffusion mechanisms of the vacancy-oxygen complex (VO) in bulk Si using ab initio calculations based on a 64-atom supercell. We found two atomic mechanisms involved in the VO diffusion; one is caused by migration of an interstitial oxygen atom, another by migration of a vacancy. The energy barrier of the mechanism due to an oxygen migration is , and that caused by a vacancy migration is . These energy barriers are close to the experimental activation energy of required for the dissociation and diffusion of VO. The derived activation energies of the two mechanisms suggest that these mechanisms plausibly occur simultaneously. In addition, we clarify that the dissociation energy of VO, , is lower than the diffusionenergy of VO.